The near universal adoption of Internet protocol (IP) as a standard for digital transmission is revolutionizing the traditional way of video delivery. Typical applications such as IPTV and live video streaming have become increasingly popular over the Internet. To efficiently utilize the bandwidth resources of the network in these applications, the video is usually compressed with suitable media coding schemes and then delivered only to subscribers who request it. For data delivery, multicast is considered the most efficient paradigm for such applications, but the scalability issue of traditional IP multicast hinders the deployment of a large-scale video delivery system with numerous channels.
Content Delivery Networks (CDNs) are also commonly used, both to provide a generic content delivery infrastructure (taking advantage of economies of scale, by aggregating content from multiple content providers) and to extend geographic footprint (allowing content providers to reach clients outside of their normal distribution area, without having to build out their own physical infrastructure). Geographic footprint extension works well when a content provider is expanding into a new locale; however, for content delivery to a sparse set of nomadic clients, footprint extension can be expensive.
Whereas the widespread adoption of CDNs has reduced latency and the amount of traffic carried by backbone networks, existing CDN technology requires content providers to delegate their valuable content and expose traffic to the CDN provider, thereby compromising end user privacy and security while revealing valuable business information. By adopting https, the content delivery process becomes more robust, and both user security and privacy improve. However, the use of end-to-end encryption takes away the ability for the network service provider to use transparent inline caches to serve previously requested content, thus increasing backbone traffic as all requests for content have to be forwarded to and served by the content provider. Large content providers can sidestep this issue by placing content on their own edge servers, but this approach is costly and increases system complexity.